Dendritic cells infected by Ad-sh-SOCS1 enhance cytokine-induced killer (CIK) cell immunotherapeutic efficacy in cervical cancer models

Regulatory Effect of JAK2/STAT3 on the Immune Function of Endotoxin-tolerant Dendritic Cells and its Involvement in Acute Liver Failure

BACKGROUND AND AIMS

Acute liver failure (ALF) is a potentially fatal clinical syndrome with no effective treatment. This study aimed to explore the role of Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) pathway in modulating the phenotype and immune function of endotoxin-tolerant dendritic cells (ETDCs). In addition, we explored the use of EDTCs in an experimental model of ALF and investigated the associated mechanisms.

METHODS

In the in vitro experiment, ETDCs were transfected with adenovirus to induce SOCS1^+/+ETDCs and SOCS1^-/-ETDCs. Thereafter, costimulatory molecules and mixed lymphocyte reaction were assessed. Experimental mice were randomly divided into normal control, ALF, ALF+mock-ETDCs, ALF+SOCS1^+/+ETDCs, ALF+AG490, and ALF+AG490+SOCS1^+/+ETDCs groups. We examined the therapeutic effect of adoptive cellular immunotherapy by tail-vein injection of target ETDCs 12 h before ALF modeling. AG490, a JAK2/STAT3 inhibitor, was used in the in vivo experiment to further explore the protective mechanism of SOCS1^+/+ETDCs.

RESULTS

Compared with control ETDCs, SOCS1^+/+ETDCs had lower expression of costimulatory molecules, weaker allostimulatory ability, lower levels of IL-6 and TNF-α expression and higher IL-10 secretion. SOCS1^-/-ETDCs showed the opposite results. In the in vivo experiments, the ALF+SOCS1^+/+ETDCs and ALF+AG490+SOCS1^+/+ETDCs groups showed less pathological damage and suppressed activation of JAK2/STAT3 pathway. The changes were more pronounced in the ALF+AG490+SOCS1^+/+ETDCs group. Infusion of SOCS1^+/+ETDCs had a protective effect against ALF possibly via inhibition of JAK2 and STAT3 phosphorylation.

CONCLUSIONS

The SOCS1 gene had an important role in induction of endotoxin tolerance. SOCS1^+/+ETDCs alleviated lipopolysaccharide/D-galactosamine-induced ALF by downregulating the JAK2/STAT3 signaling pathway.

The Antitumor Activity of CAR-T-PD1 Cells Enhanced by HPV16mE7-Pulsed and SOCS1-Silenced DCs in Cervical Cancer Models

Background

Genetically T cells modified with cancer-specific chimeric antigen receptors (CARs) showed great promise in mediate tumor regression, especially in patients with advanced leukemia. However, the therapeutic effect against solid tumors is not as prominent as anticipated to exhibit potent antitumor efficacy. The underlying mechanism maybe attributed to the inhibitory co-stimulatory pathways such as (PD1/PDL1), which provide tumor cells an escape mechanism from immunosurveillance. Therefore, by exchanging the transmembrane and cytoplasmic tail of PD1 with positive costimulatory molecules, such as CD28 and 4–1BB signaling domains (PD1-CD28-4-1BB, PD1-CAR), the T cell-negative co-stimulatory PD1/PDL1 signal pathway was thus converted into a positive one. This study aimed to investigate whether the genetically modified CAR-T-PD1 cells activated by SOCS1 silenced DCs have enhanced anti-neoplastic potential in vitro/in vivo.

Methods

In order to enhance the antigenicity and reduce transformation activity, a modified HPV16 E7 (HPV16mE7) was employed to load on dendritic cells (DCs) with SOCS1 silenced to improve its antitumor efficiency and targeting ability against cervical cancer. The CAR-T-PD1 cells activated by the generated DCs were transfused into murine models bearing tumor of CaSki cells that expressing PDL1 and HPV16 E6/E7 for in vitro/in vivo antitumor activity assay.

Results

The data showed that DC-activated CAR-T-PD1 cells significantly increased the secretion of IL-2, IFN-γ and TNF-α, whilst enhanced cytotoxic activity, suppressed tumor growth and prolong the survival time compared with the controls.

Conclusion

These results indicated that the genetically engineered T cells activated by DCs had improved antitumor efficiency and targeting ability. Furthermore, it was suggested that it may have important implications for the improvement of T cell immunotherapy against cervical cancer.

Targeted Gene Delivery Therapies for Cervical Cancer

Despite being largely preventable through early vaccination and screening strategies, cervical cancer is the most common type of gynecological malignancy worldwide and constitutes one of the leading causes of cancer deaths in women. Patients with advanced or recurrent disease have a very poor prognosis; hence, novel therapeutic modalities to improve clinical outcomes in cervical malignancy are needed. In this regard, targeted gene delivery therapy is presented as a promising approach, which leads to the development of multiple strategies focused on different aspects. These range from altered gene restoration, immune system potentiation, and oncolytic virotherapy to the use of nanotechnology and the design of improved and enhanced gene delivery systems, among others. In the present manuscript, we review the current progress made in targeted gene delivery therapy for cervical cancer, the advantages and drawbacks and their clinical application. At present, multiple targeted gene delivery systems have been reported with encouraging preclinical results. However, the translation to humans has not yet shown a significant clinical benefit due principally to the lack of efficient vectors. Real efforts are being made to develop new gene delivery systems, to improve tumor targeting and to minimize toxicity in normal tissues.

The Immunotherapeutic Effect of SIRPα-Silenced DCs against Cervical Cancer

Signal regulatory protein α (SIRPα), a transmembrane protein that is predominantly expressed in dendritic cells (DCs) or macrophages, interacts with CD47 that is overexpressed in almost all types of tumor cells. The interaction between SIRPα and CD47 leads to a negative signal that prevents the phenotypic and functional maturation of DC and inhibits phagocytosis. The SIRPα knockdown in DCs that were pulsed with a modified HPV16E7 (HPV16mE7) protein with enhanced antigenicity and reduced transformation activity results in increased cytokine (TNF-α/IL-12/IL-6) secretion, IFN-γ secretion by T lymphocytes, and in vitro/in vivo tumoricidal activity against cervical cancer cells. Taken together, these results suggest that SIRPα-silenced DC vaccination presented potential therapeutic implications against cervical cancer.